Eight people were killed and a dozen others injured yesterday when an off-road truck ploughed into a crowd during a California desert race.

The crash came shortly after the start of the California 200, a Saturday evening race in the Mojave desert, said Cindy Bachman, San Bernardino county sheriff's spokeswoman. Bachman said several of the injured were in a serious condition.

"There was dust everywhere, people screaming, people running," David Conklin, a photographer at the event, said.

Conklin said the Prerunner truck was among the first 20 vehicles off the starting line in the race, which began at about 8pm local time. He said the vehicle had just gone over a jump known as "the rockpile", which is about two miles into the race, when he said he saw the vehicle sail through the air. When he turned to watch for other cars he heard the commotion caused by the crash, he explained.

"When I got up to the vehicle I could tell that several people were trapped. There were just bodies everywhere," he said.

"One woman with a major head wound [was] lying in a pool of blood. Another was crushed beneath the car."

The truck came to a rest upside down with its oversized wheels pointing towards the sky. Spectators rushed towards it and about half a dozen people flipped it upright to help at least one person pinned underneath. Officials said the driver was not hurt but had to flee the accident scene to escape angry spectators.

It took rescue vehicles and helicopters more than half an hour to reach the remote location, and spectators including off-duty police and firefighters helped the injured and placed blankets over the dead. Six people died at the scene and two others died after being taken to a hospital, authorities said.

The 200-mile race is part of a series held in the Mojave desert's Soggy Dry Lake Bed near the city of Lucerne Valley, 100 miles north-east of Los Angeles.

Tens of thousands of people attend the California 200, in which a variety of off-road vehicles tackle jumps and other obstacles, reaching speeds of up to 100mph on the 50-mile off-road course.

The California 200 was scheduled to last throughout the night.

The race crowd was apparently standing within three metres of the track without guard rails separating them from the speeding vehicles. "There were no barriers at all," Jeff Talbott, inland division chief for the California Highway Patrol, told the Riverside Press-Enterprise.

He said the driver, Brett M Sloppy, 28, who is from the San Diego area, was forced to run from the scene when the crowd grew angry. Some spectators threw rocks at him, he said. It was not clear why the driver had lost control of the truck. Authorities said alcohol was not a factor and there were no plans to arrest Sloppy.

The California Highway Patrol does not normally investigate crashes at organised race events. The Federal Bureau of Land Management was assisting in the investigation.

The crash was the latest in a series of fatal race accidents.

A car ploughed into a crowd at an illegal drag race on a suburban road in Accokeek, Maryland, in February 2008, killing eight people and injuring five.

The two drivers were charged with vehicular manslaughter. Darren Bullock, 22, was sentenced to 15 years in prison; Tavon Taylor, 20, is awaiting trial.

In Chandler, Arizona, a female spectator was killed by a tyre that flew off a crashing drag car at the NHRA Arizona Nationals, in February.

In Selmer, Tennessee, a drag car spun out of control and careered into spectators during a fundraising festival in June 2007, killing six people and injuring 22. The driver received 18 months' probation.